ABSTRACT: Surficial geology, Halifax Harbour, Nova Scotia.

CGRG Bibliography of Canadian Geomorphology
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Abstract

The marine geology of Halifax Harbour, Nova Scotia, was studied using seismic-reflection profiles, sidescan-sonar systems, multibeam bathymetry, seabed samples, cores, and photographic observations. Dating of core material and information from seabed samples were correlated with the stratigraphic information from the seismic-reflection data and multibeam backscatter. Maps of detailed multibeam bathymetry, seabed slope, sediment distributions, and both natural and anthropogenic seabed features and processes are presented. The surficial geology of Halifax Harbour results from glacial erosion and deposition during ice advance and retreat across a former fluvial drainage system, subsequent glaciomarine and lacustrine deposition, erosion by a marine transgression, and recent sedimentation. The outer harbour largely consists of coarse, well sorted sand and gravel with bedrock outcrop in many areas. Sand ribbons, megaripples, and gravel circles form in response to currents and waves. In contrast, the inner harbour consists of gas-charged Holocene mud and is covered with anchor marks, dredge spoils, shipwrecks, cables, and other debris. Natural features include sedimentary furrows, drumlins, moraines, pockmarks, and former shorelines. The inner harbour largely traps sediments and their associated contaminants and minimal amounts are transported out of the harbour. Halifax Harbour is one of the first marine areas in Canada to have been studied with multibeam bathymetry. It provides a high-resolution portrayal of seabed morphology and features that are interpreted from a morphodynamic perspective. Net sediment transport is dominantly from south to north. The seabed sediment mapping and assessment of anthropogenic features provides a basis for management of Halifax Harbour including marine habitats.

Bibliography of Canadian Geomorphology